# -*- coding: utf-8 -*-
# © 2012 Therp BV (<http://therp.nl>)
# License AGPL-3.0 or later (http://www.gnu.org/licenses/gpl.html).

import re

from odoo import models, fields, api, _, SUPERUSER_ID
from odoo.exceptions import UserError
import logging

_logger = logging.getLogger('orm.ldap')

try:
    import ldap
    from ldap.filter import filter_format
except ImportError:
    _logger.debug('Cannot import ldap.')


class CompanyLDAP(models.Model):
    _inherit = 'res.company.ldap'

    no_deactivate_user_ids = fields.Many2many(
        comodel_name='res.users',
        relation='res_company_ldap_no_deactivate_user_rel',
        column1='ldap_id',
        column2='user_id',
        string='Users never to deactivate',
        help='List users who never should be deactivated by'
             ' the deactivation wizard',
        default=lambda self: [(6, 0, [SUPERUSER_ID])],
    )
    deactivate_unknown_users = fields.Boolean(
        string='Deactivate unknown users',
        default=False,
    )

    @api.multi
    def action_populate(self):
        """
        Prepopulate the user table from one or more LDAP resources.

        Obviously, the option to create users must be toggled in
        the LDAP configuration.

        Return the number of users created (as far as we can tell).
        """
        _logger.debug(
            "action_populate called on res.company.ldap ids %s", self.ids)
        users_model = self.env['res.users']
        users_count_before = users_model.search_count([])
        deactivate_unknown, known_user_ids = self._check_users()
        if deactivate_unknown:
            _logger.debug("will deactivate unknown users")
        for conf in self.get_ldap_dicts():
            if not conf['create_user']:
                continue
            attribute_match = re.search(
                r'([a-zA-Z_]+)=\%s', conf['ldap_filter'])
            if attribute_match:
                login_attr = attribute_match.group(1)
            else:
                raise UserError(
                    _("No login attribute found: "
                      "Could not extract login attribute from filter %s") %
                    conf['ldap_filter'])
            results = self.get_ldap_entry_dicts(conf)
            for result in results:
                login = result[1][login_attr][0].lower().strip()
                user_id = self.with_context(
                    no_reset_password=True
                ).get_or_create_user(conf, login, result)
                if not user_id:
                    # this happens if the user exists but is active = False
                    # -> fetch the user again and reactivate it
                    self.env.cr.execute(
                        "SELECT id FROM res_users "
                        "WHERE lower(login)=%s",
                        (login,))
                    res = self.env.cr.fetchone()
                    _logger.debug('unarchiving user %s', login)
                    if res:
                        self.env['res.users'].sudo().browse(
                            res[0]
                        ).write(
                            {'active': True}
                        )
                        user_id = res[0]
                    else:
                        raise UserError(
                            _("Unable to process user with login %s") % login
                        )
                known_user_ids.append(user_id)
        users_created = users_model.search_count([]) - users_count_before

        deactivated_users_count = 0
        if deactivate_unknown:
            deactivated_users_count = \
                self.do_deactivate_unknown_users(known_user_ids)

        _logger.debug("%d users created", users_created)
        _logger.debug("%d users deactivated", deactivated_users_count)
        return users_created, deactivated_users_count

    def _check_users(self):
        ldap_config = self.search([])
        deactivate_unknown = None
        known_user_ids = [self.env.user.id]
        for item in ldap_config.read(
                ['no_deactivate_user_ids',
                 'deactivate_unknown_users'],
                load='_classic_write'):
            if deactivate_unknown is None:
                deactivate_unknown = True
            known_user_ids.extend(item['no_deactivate_user_ids'])
            deactivate_unknown &= item['deactivate_unknown_users']
        return deactivate_unknown, known_user_ids

    def get_ldap_entry_dicts(self, conf, user_name='*', timeout=60):
        """Execute ldap query as defined in conf.

        Don't call self.query because it supresses possible exceptions
        """
        ldap_filter = filter_format(conf['ldap_filter'] % user_name, ())
        conn = self.connect(conf)
        ldap_password = conf['ldap_password'] or ''
        ldap_binddn = conf['ldap_binddn'] or ''
        conn.simple_bind_s(
            ldap_binddn.encode('utf-8'),
            ldap_password.encode('utf-8')
        )
        results = conn.search_st(
            conf['ldap_base'].encode('utf-8'),
            ldap.SCOPE_SUBTREE,
            ldap_filter.encode('utf8'),
            None,
            timeout=timeout
        )
        conn.unbind()
        return results

    def do_deactivate_unknown_users(self, known_user_ids):
        """Deactivate users not found in last populate run."""
        unknown_user_ids = []
        known_user_ids = list(set(known_user_ids))
        users = self.env['res.users'].sudo().search(
            [('id', 'not in', known_user_ids)], order='login')
        ldap_confs = self.get_ldap_dicts()
        for unknown_user in users:
            _logger.debug('checking user %s', unknown_user.login)
            present_in_ldap = any(
                bool(
                    self.get_ldap_entry_dicts(
                        conf,
                        user_name=unknown_user.login,
                    ))
                for conf in ldap_confs
            )
            if not present_in_ldap:
                _logger.debug('archiving user %s', unknown_user.login)
                unknown_user.active = False
                unknown_user_ids.append(unknown_user.id)
        return len(unknown_user_ids)

    @api.multi
    def populate_wizard(self):
        """
        GUI wrapper for the populate method that reports back
        the number of users created.
        """
        if not self:
            return
        wizard_obj = self.env['res.company.ldap.populate_wizard']
        res_id = wizard_obj.create({'ldap_id': self.id}).id

        return {
            'name': wizard_obj._description,
            'view_type': 'form',
            'view_mode': 'form',
            'res_model': wizard_obj._name,
            'domain': [],
            'context': self.env.context,
            'type': 'ir.actions.act_window',
            'target': 'new',
            'res_id': res_id,
            'nodestroy': True,
        }
